The increasing use of graphics in computer user interfaces (Graphical User Interfaces) poses a major problem for blind computer users. While text to Braille and text to voice devices are available, access to complex computer graphics is currently virtually impossible. The uniquely flexible electrotactile research tool developed by Unitech Research, Inc. is expected to accelerate the development of electrotactile devices, and will be the foundation of the proposed research. The Phase II research proposed is two-fold: to map the complex relationship (revealed in the Phase l research) of the electrotactile waveform to the percept, as it pertains to displaying graphical concepts such as overlapping windows, selected objects, etc., and to develop a working prototype of a Windows(TM) (or in the future, Macintosh(TM)) electrotactile Graphical User Interface. The prototype will be developed with congenitally blind, adventitiously blind and sighted subjects. The outcome of the research will enable us to better hone the functional characteristics of the technology, as well as provide prospects for enhanced spatial perception in the blind.